High efficiency thermodynamic system

ABSTRACT

An air-handling system selectively heats and/or cools a target space by circulating ambient air from the target space across a heat exchanger. The system operates along an air flow path having an inlet from the target space and an outlet back into the target space. Air-handling turbines or pumps are located near the inlet and outlet. The heat exchanger is placed in the flow path between the turbines or pumps. The heat exchanger transfers heat into or out of the air, causing a natural pressure increase or decrease in the air. The turbines or pumps are configured to harvest work from the induced pressure differential in order to conserve energy. A combustion chamber may be included directly in the flow path upstream of the heat exchanger for combusting a fuel in the air during a high heating mode.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. Ser. No. 12/917,064 filedNov. 1, 2010, now US 2011/0100011 published May 5, 2011, which claimspriority to Provisional Patent Application No. 61/256,559 filed Oct. 30,2009, the entire disclosures of which are hereby incorporated byreference and relied upon.

BACKGROUND OF THE INVENTION

1. Field of the Invention

A thermodynamic system for selectively heating and/or cooling a targetspace, and more particularly such a thermodynamic system in whichambient air comprises the working fluid therefor.

2. Description of Related Art

Thermodynamic systems in the form of heat pumps are used in the priorart to alternatively heat or cool a target space in standardheating/cooling modes. Heat pumps generally include a compressor, twoheat exchangers, and an expander all disposed in a common fluid flowpath. Most heat pump systems are of the closed loop type in which theworking fluid, typically a two-phase refrigerant, is circulated throughthe system so as to absorb heat through one of the heat exchangers andto reject heat from the other heat exchanger. When the target space isto be heated, the system is configured so that the heat exchanger thatrejects heat will be stationed in the target space or in thermodynamiccommunication therewith such as via suitable plumping or ducting.Alternatively, when the target space is to be cooled, the system isconfigured so that the heat exchanger that rejects heat will bestationed in (or ducted to) the ambient environment or other suitableheat sink. Both configurations are considered within a standardheating/cooling mode. Not all heat pump systems are of the closed looptype; some heat pump systems have been proposed in an open-looparrangement using ambient air as the working fluid.

A target space may be any enclosed or localized space. The target spacemay be a human environment, such as a building or the passengercompartment in an automobile. Alternatively, the target space may be arelatively small or large area for objects like a personal computerenclosure or a server room.

While such known heat pump systems are adequate in many climates, theyare frequently unable to provide adequate heating during extremely coldconditions. This is because a typically sized system is not capable ofcooling the working fluid (even in the case of a hazardous refrigerant)to a cold enough temperature so that it has capacity to absorb heat froman exceptionally cold ambient atmosphere. In these conditions, it may benecessary to supplement the heat pump with a secondary furnace, stove,or other heating apparatus to adequately heat the target space.

U.S. Pat. No. 3,686,893, issued to Thomas C. Edwards on Aug. 29, 1972and U.S. Pat. No. 4,008,426, issued to Thomas C. Edwards on May 9, 1978(hereinafter referred to as “the Edwards patents”), show a positivedisplacement rotating vane-type device that operates a thermodynamiccycle for simultaneously compressing and expanding a working fluid whichmay be air. The devices shown in the Edwards patents each have a statorhousing and a rotor disposed in the stator housing defining aninterstitial space therebetween. A plurality of vanes are operativelydisposed between the rotor and the stator housing for dividing theinterstitial space into revolving compression and expansion chambers.The vanes are spring loaded to slidably engage the inner wall of thestator housing. The rotor is rotatably disposed within the statorhousing for rotating in a first direction. While the rotor is rotating,the vanes slide along the inner wall of the stator housing andsimultaneously compress the working fluid in the compression chambersand expand the fluid in the expansion chambers.

The stator housing of the Edwards patents further define several portsfor conducting the working fluid into and out of the device. These portsinclude a compression chamber inlet, a compression chamber outlet, anexpansion chamber inlet, and an expansion chamber outlet. Additionally,the stator housing of the Edwards patents defines an expansion chamberinlet and an expansion chamber outlet. The compression chamber inlet andthe expansion chamber outlet are both disposed on the side of the statorhousing and communicate with different chambers. Thus, the working fluidenters and exits the device of the Edwards patents through various portsin a carefully arranged radial direction.

The Edwards patents are typical of prior art positive displacementrotating vane-type devices where the transfer of working fluid into andout of the device via ports is accomplished though localized piping thatis arranged to prevent inadvertent mixing of high and low pressurefluids. Elaborate seals and other measures are sometimes taken to ensurethe high and low pressure fluids never mix, and thereby reduce operatingefficiencies. Such measures add considerably to the complexity and costof positive displacement rotating vane-type devices.

There exists a need for further efficiency improvements in the field ofheat pump systems, and more particularly for air-aspirated systems inwhich ambient air serves as the working fluid. There exists a need for aheat pump system that can fully meet the heating needs of a target spaceduring very cold conditions. Furthermore, there exists a need for a heatpump system that is capable of efficiently transferring a working fluid(be it air or otherwise) between high and low pressure ports of apositive displacement rotating vane-type device without unnecessarycomplexity or cost.

BRIEF SUMMARY OF THE INVENTION

The invention comprises a high-efficiency air moving system forcirculating ambient air in a target space across a heat exchanger. Aconfined flow path is established for routing ambient air as a workingfluid from an inlet to an outlet. In this configuration, the inlet isdisposed to receive ambient air from the target space as the workingfluid and the outlet is disposed for expelling the air out of the flowpath and back into the ambient air in the target space. A first turbineor pump is disposed in the flow path adjacent the inlet. The firstturbine or pump is configured to control substantially all of themovement of air entering the flow path through the inlet. A secondturbine or pump is disposed in the flow path adjacent the outlet. Thesecond turbine or pump is configured to control substantially all of themovement of air exiting the flow path through the outlet. A heatexchanger is located in the flow path between the first and secondturbines or pumps. The heat exchanger is configured to move heat into orout of the air in the flow path and thereby heat or cool the air in thetarget space when the air is subsequently discharged from the outlet.The addition or subtraction of heat in the flow path via the heatexchanger causes a corresponding pressure increase or pressure decrease,respectively, in the air between the first and second turbines or pumpsrelative to the ambient air. The improvement of this invention comprisesat least one of the first turbine or pump and the second turbine or pumpbeing configured to harvest work from the differentiated pressure of theair between the first and second turbines.

The system of the present invention enables a more efficient air movingsystem than air moving systems of the prior art because it utilizes atleast two turbines or pumps on opposite sides (i.e., upstream anddownstream) of a heat exchanger that are configured to reclaim availablepressure energy from the working fluid caused by the addition orsubtraction of heat. As a result, the system is more readily adapted toheat or cool a target space while concurrently conserving energy byharvesting at least some of the residual energy in the working fluidthat exists in the form of a pressure differential above the ambientatmospheric conditions.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

These and other features and advantages of the present invention willbecome more readily appreciated when considered in connection with thefollowing detailed description and appended drawings, wherein:

FIG. 1 is a view showing an air aspirated hybrid heat pump and heatengine system according to an embodiment of this invention;

FIG. 2 is a simplified, partially exploded view of a positivedisplacement rotating vane-type device as in FIG. 1 but configured in aclosed-loop arrangement;

FIG. 3 shows an alternative embodiment of the invention wherein thepositive displacement rotating vane-type device of FIG. 1 is configuredin a cooling mode;

FIG. 4 is a view as in FIG. 3 but where the device is configured in aheating mode; and

FIG. 5 is yet another alternative embodiment of the air aspirated hybridheat pump and heat engine system utilizing independent compressor andexpander devices to achieve either a fixed or variable asymmetriccompression/expansion ratio.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the Figures, wherein like numerals indicate correspondingparts throughout the several views, one embodiment of the invention isshown in FIG. 1 as an open loop air aspirated hybrid heat pump and heatengine system 20 for selectively heating and cooling a target space 22.The target space 22 can be an interior room in a building, the passengercompartment of an automobile, a computer enclosure, or any otherlocalized space to be heated and/or cooled. The working fluid of thesystem 20 in this embodiment is most preferably air, however in generalthe principles of this invention will permit other substances to be usedfor the working fluid including multi-phase refrigerants in suitableclosed-loop configurations.

The hybrid heat pump and heat engine system 20 includes a working fluid(e.g., air) flow path 24, generally indicated in FIG. 1, extending froman inlet 26 to an outlet 28. The inlet 26 receives working fluid (air inthis example) from an ambient source 30, while the outlet 28 dischargesair from the system 20 back to the ambient environment 30. Preferably,the inlet 26 and outlet 28 are both disposed outside of the target space22 and in the atmosphere 30 when atmospheric air is used as the workingfluid.

A heat exchanger 32 is disposed in the flow path 24 between the inlet 26and the outlet 28. In the exemplary embodiment of FIG. 1, the heatexchanger 32 is disposed in the target space 22 for transferring heatbetween the target space 22 and the working fluid in the flow path 24.In a standard heating/cooling mode of operation, the system 20 isconfigured to either transfer heat from the working fluid to the targetspace 22 to heat the target space 22 or alternatively to transfer heatfrom the target space 22 to the working fluid to cool the target space22. The heat exchanger 32 is preferably a high efficiency heat exchanger32 having a large surface area, such as by plurality of fins, forconvectively transferring heat between air in the target space 22 andthe working fluid in the flow path 24. Preferably, a fan 34 or a bloweris disposed adjacent to the heat exchanger 32 for propelling the air inthe target space 22 through the heat exchanger 32 to assist in the heatexchange between the air in the target space 22 and the air in the heatexchanger 32. Of course, conductive methods of heat transfer can also beused instead of or in addition to convective methods suggested by thefan 34 in the target space 22 in FIG. 1.

In the exemplary embodiment of FIG. 1, a positive displacement rotatingvane-type device 36 is disposed in the flow path 24 for simultaneouslycompressing and expanding the air. While a positive displacement typedevice 36 is preferred for all implementations of this invention, somealternative embodiments of the invention as applied to the hybrid heatpump principles described below may substitute a blower that is not ofthe positive displacement variety in place of the positive displacementrotating vane-type device 36. Such substitution is enabled by the heatpump principles of this invention which deal with what can be considereda very low pressure ratio Brayton Cycle. As such, those of skill in theart will appreciate that a common fan or blower could be effective atmaintaining a suitable pressure differential, namely on the order ofAtmospheric plus or minus 20-30%. Of course, efficiently losses would beexpected to be greater with common fan or blower devices, but such maybe acceptable in certain applications.

The vane-type device 36 includes a generally cylindrical stator housing38 longitudinally between spaced and opposite ends 40. A rotor 42 isdisposed within the stator housing 38 and establishes an interstitialspace 22 between the rotor 42 and the inner wall 44 of the statorhousing 38. A plurality of vanes 46 are operatively disposed between therotor 42 and the stator housing 38 for dividing the interstitial space22 into intermittent compression and expansion chambers 48, 50. Thevanes 46 are spring loaded to slidably engage the inner wall 44 of thestator housing 38. Accordingly, the plurality of compression 48 andexpansion 50 chambers are each defined by a space between two adjacentvanes 46. As the rotor 42 rotates relative to the stator housing 38, thechambers 48, 50 defined between adjacent vanes 46 sequentially andprogressively transition between compression and expansion stages in acontinuum so that the working fluid is simultaneously compressed incompression chambers and expanded in expansion chambers. That is to say,at any time during rotation of the rotor 42, working fluid is beingcompressed in one portion of the device 36 and expanded in anotherportion of the device 36.

Two arcuately spaced transition points correspond with maximumcompression and maximum expansion of the working fluid. In theparticular embodiment illustrated in FIG. 1, these transition pointsoccur at the 12 o'clock and 6 o'clock positions of the stator housing38, with the 12 o'clock position being the point of maximum expansionand the 6 o'clock position being the point of maximum compression. Inalternative configurations of the rotary device 36, there may be onlyone transition point corresponding to either maximum compression ormaximum expansion, such as in systems like that shown in FIG. 5 were thecompression and expansion functions are carried out in separate devices.Or, there may be three or more transition points where a rotary deviceincorporates multiple lobes as shown for example in U.S. Pat. No.7,556,015 to Staffend, issued Jul. 7, 2009, the entire disclosure ofwhich is hereby incorporated by reference. In any case, therefore, thetransition points may be defined as the rotary positions where thechambers 48, 50 between adjacent vanes 46 transition between thecompression and expansion stages, respectively.

Working fluid ports are provided to move the working fluid into and outof the device 36. In the embodiment illustrated in FIG. 1, the portsinclude a compression chamber inlet 52, a compression chamber outlet 54,an expansion chamber inlet 56, and an expansion chamber outlet 58. Thecompression chamber inlet 52 and expansion chamber outlet 58 are locatedadjacent to the 12 o'clock position transition point corresponding tomaximum expansion. By contrast, the expansion chamber inlet 56 andcompression chamber outlet 54 are located adjacent to the 6 o'clockposition transition point corresponding to maximum expansion. Thecompression chamber inlet 52 is in fluid communication with the inlet 26for receiving the atmospheric air, and the expansion chamber outlet 58is in fluid communication with the outlet 28 for discharging the air outof the flow path 24 to the atmosphere 30. The heat exchanger 32 is influid communication with the vane-type device 36 through the compressionchamber outlet 54 and the expansion chamber inlet 56.

The compression chamber inlet 52 and the expansion chamber outlet 58 aregenerally longitudinally aligned with one another relative to the statorhousing 38 for simultaneously communicating with the same chamber 48,50. In other words, the compression chamber inlet 52 and the expansionchamber outlet 58 may be located on opposite longitudinal ends of thestator housing 38 so as to communicate simultaneously with a commonchamber or chambers 48, 50. Thus a compression chamber port (inlet 52 inthis example) and an expansion chamber port (outlet 58 in this example)are continuously in communication with at least one common chamber at ornear a transition point. A pump 60 may be disposed in the flow path 24between inlet 26 and the compression chamber inlet 52 for propelling theworking fluid into the stator housing 38 through the compression chamberinlet 52. The arrangement of the ports according to this inventionenable a greater fractional use of the swept volume of the rotatingvane-type device. Furthermore, the flow of working fluid through thedevice 36 is improved.

The rotor 42 is rotatably disposed within the stator housing 38 forrotating in a first direction. While the rotor 42 is rotating, the vanes46 slide along the inner wall 44 of the stator housing 38 andsimultaneously reduce the volume of the compression chambers 48 andincrease the volume of the expansion chambers 50. In the exemplaryembodiment, vane-type device 36 accomplishes the simultaneouscompression and expansion because the cross-section of the inner wall 44of the stator housing 38 is circular and the rotor 42 rotates about anaxis A that is off-set from the center of the circular inner wall 44.Alternatively, the stator housing 38 could be elliptically shaped andthe rotor 42 could rotate about the center of the elliptical statorhousing 38. Other configurations are of course possible, including thosedescribed in U.S. Pat. No. 7,556,015 as well as those described inpriority document U.S. Provisional Application Ser. No. 61/256,559 filedOct. 30, 2009, the entire disclosure of which is hereby incorporated byreference and relied upon.

The embodiment of FIG. 1 can operate in a standard heating/cooling modeor in an optional high heating mode. In the standard heating/coolingmode, the pump 60 propels atmospheric air into the vane-type device 36through the compression chamber inlet 52. The temperature and pressureof the air both increase as the air is compressed in the compressionchambers 48 before exiting the device 36 through the compression chamberoutlet 54. The pressurized and warmed air flows passively through adormant combustion chamber 62 and then to the heat exchanger 32 where itdispenses heat to warm the target space 22. Exiting the heat exchanger32, the cooled but still pressurized air then flows back to the device36 and enters the stator housing 38 via the expansion chamber inlet 56at or near the 6 o'clock transition point. The air is directed into thenext available expansion chamber 50 where is carried and swept in anexpanding volume to depressurize, preferably back to the atmosphericpressure. Available pressure energy in the working fluid is thusreleased from the working fluid to act on the rotor 42 as a torque andthereby directly offset the energy required on the compression side ofthe rotor 42 working to simultaneously compress the working fluid inchambers 48.

Next, the air is pushed out of the vane-type device 36 through theexpansion chamber outlet 58 by the air entering the vane-type device 36through the compression chamber inlet 52. Finally, the air is dischargedto the atmosphere 30 through the outlet 28. The difference in thepressure of the air entering the expansion chambers 50 and theatmospheric pressure represents potential energy. The expansion chambers50 of the vane-type device 36 harness that potential energy and use itto provide power to the rotor 42.

The system includes a combustion chamber 62 in the flow path 24 betweenthe compression chamber outlet 54 of the vane-type device 36 and theheat exchanger 32. During the standard heating/cooling mode, describedabove, the combustion chamber 62 remains dormant. However, during anoptional high heating mode, a fuel introduced into the combustionchamber 62 is combusted, or burned, in the working fluid to greatlyincrease both its temperature and pressure within the flow path 24. Thefuel may be any suitable type including for examples natural gas,propane, gasoline, methanol, grains, particulates or other combustiblematerials.

The compression chambers 48 of the vane-type device 36 compress the airby a first predetermined ratio, and the expansion chambers 50 of thevane-type device 36 expand the air by a second predetermined ratio. Inthe FIG. 1 embodiment, the first and second predetermined ratios areapproximately equal to one another. When accounting for heat transfersand losses, the equal expansion/compression ratios are adequate toextract all available work energy from the fluid during the standardheating/cooling modes of operation. However, following the combustion ofair in the combustion chamber 62 during the high heating mode, thepressure of the air in the flow path 24 is substantially elevated suchthat the vane-type device 36 cannot be expected to fully (or nearlyfully) depressurize all of the air in the flow path 24 back to theatmospheric pressure. Therefore, a secondary expander 66 may be providedto receive surplus working fluid. The secondary expander 66 may belocated downstream of a valve 64 disposed in a spur flow path adjoiningthe main flow path 24 extending between the heat exchanger 32 and theexpansion chamber inlet 56. During the standard heating/cooling mode,the valve 64 may be closed to direct all of the working fluid in theflow path 24 from the heat exchanger 32 to the expansion chamber inlet56. Although not shown, a pressure regulator may be included in the flowpath 24 leading to the expansion chamber inlet 56, and the valve 64 mayoperate in conjunction with the pressure regulator to open when thepressure regulator reaches a maximum pressure threshold. During the highheating mode when excesses of pressure are generated in the workingfluid, the valve 64 is manipulated (either automatically or manually) todirect a portion of the working fluid from the heat exchanger 32 to asecondary expander 66. The remaining portion of the working fluidtravels to the expansion chamber inlet 56 as described above. Thus, inorder to improve the energy efficiency of the system, it is advantageousto redirect at least some of the pressurized air from the heat exchanger32 to the secondary expander 66, which is mechanically connected to anenergy receiving device, here an electric generator 68, and therereclaimed. Preferably, all of the surplus working fluid, i.e., thatportion of the working fluid that cannot be fully expanded to ambientpressure in the expansion chambers 50, is directed to the secondaryexpander 66 where potential energy in the working fluid is convertedinto another useful form of energy. The vane-type device 36 and theelectric generator 68 work together to capture and convert any residualpressure energy remaining in the working fluid before it is dischargedto ambient 30.

In operation, during the high heating mode, the pump 60 propelsatmospheric air into the vane-type device 36 through the compressionchamber inlet 52. The temperature and pressure of the air both increaseas the air is compressed in the compression chambers 48. The pressurizedand warmed air then exits the vane-type device 36 through thecompression chamber outlet 54 and flows into the combustion chamber 62.In the combustion chamber 62, the fuel is mixed with the air andcombusted to greatly increase the pressure and temperature of the air.The air then flows through the heat exchanger 32 where it dispenses heatto warm the target space 22. Next, the valve 64 directs a predeterminedamount of the air to the expansion chamber inlet 56 of the vane-typedevice 36 and the remaining air to the secondary expander 66. In thevane-type device 36, the pressurized air is expanded, preferably to ornearly to the atmospheric pressure, before it is discharged out of theflow path 24 and to the atmosphere 30 through the outlet 28. A secondaryheat exchanger (not shown) may be incorporated into the flow path 24between the expansion chamber outlet 58 and the flow path outlet 28 toscavenge any remaining heat in the working fluid and thereby furtherincrease thermodynamic efficiencies. Ideally, the temperature of theworking fluid as it emerges from the outlet 28 is at or only veryslightly greater than the ambient air temperature. The air in thesecondary expander 66 is also expanded, preferably to or nearly toatmospheric pressure, while powering the generator 68 to produceelectricity. After the air is expanded by the secondary expander 66, itis also directed to the outlet 28 to be discharged to the atmosphere 30.

Through reconfiguration, the embodiment of FIG. 1 can also work in acooling capacity in its standard heating/cooling mode. There are manyways to reconfigure the system. One way to switch the system to thecooling operating mode is to rotate the vane-type device 36 by onehundred and eighty degrees (180°). In another technique, the rotor 42could be moved in a radially upward direction (i.e., shifted upward)while the stator housing 38 remains stationary. Both of thesereconfiguration methods effectively transform the compression chambers48 into the expansion chambers 50 and vice versa. When operating in thecooling operating mode, the pump 60 first propels the atmospheric airinto the expansion chambers 50 of the vane-type device 36 to reduce thepressure and temperature of the air. The combustion chamber 62 isdormant. The cooled air receives heat from the heat exchanger 32 to coolthe target space 22. The air is then re-pressurized in the compressionchambers 48 of the vane-type device 36, preferably to atmosphericpressure, before being dispensed to the atmosphere 30 through the outlet28.

The vane-type device 36 can also work in a closed loop system 70, asgenerally shown in FIG. 2. In the closed loop system 70, the workingfluid may be air or a refrigerant. Like the open-loop system of FIG. 1,the compression chamber inlet 52 and expansion chamber outlet 58 aregenerally longitudinally aligned with one another for simultaneouslycommunicating with the same chamber 48, 50. A high-pressure side heatexchanger 72 is fluidly connected to the vane-type device 36 through thecompression chamber outlet 54 and the expansion chamber inlet 56. Alow-pressure side heat exchanger 74 is fluidly connected to thevane-type device 36 through the expansion chamber outlet 58 and thecompression chamber inlet 52.

The closed loop system 70 FIG. 2 has two operating modes: a firstoperating mode and a second operating mode. Either the high pressureside heat exchanger 72 or the low-pressure side heat exchanger 74 may bedisposed in a target space to be selectively heated or cooled or outsideof the target space in the atmosphere.

In the first operating mode, the rotor 42 rotates in a first direction,causing the pressure and temperature of the working fluid in thecompression chambers 48 to increase as the volume of those compressionchambers 48 decreases. That working fluid then flows into thehigh-pressure side heat exchanger 72 where it dissipates heat to eitherthe target space or the atmosphere. The pressurized and cooled workingfluid then flows into the expansion chambers 50 through the expansionchamber inlet 56. In the expansion chambers 50, the temperature and thepressure of the working fluid decrease as the volume of the expansionchambers 50 increases. The working fluid leaves the expansion chambers50 through the expansion chamber outlet 58 and flows to the low-pressureside heat exchanger 74. In the low-pressure side heat exchanger 74, theworking fluid receives heat from either the target space or theatmosphere before flowing back into the compression chambers 48.

Similar to the open loop embodiment of FIG. 1, the vane-type device 36of FIG. 2 can be switched to the second operating mode throughreconfiguring. Specifically, the vane-type device 36 can be rotated byone hundred and eighty degrees (180°), or the rotor 42 could be movedradially within the stator housing 38. This reconfiguring effectivelyreverses the functionality of the high-pressure side heat exchanger 72and the low-pressure side heat exchanger 74. In other words, thelow-pressure side heat exchanger 74 becomes the high-pressure side heatexchanger 72 and dissipates heat, and the high-pressure side heatexchanger 32, 72 becomes the low-pressure side heat exchanger 74 andreceives heat.

FIG. 3 shows the vane-type device 36 in a cooling open-loop system.Similar to the embodiment of FIG. 1, air is used as the working fluid inthe embodiment of FIG. 3. Unlike the embodiment of FIG. 1, the inlet 26and the outlet 28 are disposed in the target space 22 for using air fromthe target space 22 as the working fluid. In the embodiment of FIG. 3,the compression chamber inlet 52 of the stator housing 38 is generallylongitudinally aligned with the expansion chamber outlet 58 of thestator housing 38. A heat exchanger 32 disposed in the atmosphere 30 isfluidly connected to the vane-type device 36 through the compressionchamber outlet 54 and the expansion chamber inlet 56. In operation, theair in the target space 22 enters the flow path 24 through the inlet 26,and the blower propels the air into the vane-type device 36 through thecompression chamber inlet 52. The pressure and temperature of the airincrease as the volume of the compression chambers 48 decreases. The airleaves the vane-type device 36 through the compression chamber outlet 54and flows to the heat exchanger 32. In the heat exchanger 32, the warmedand pressurized air dispenses heat to the atmosphere 30 before flowingback into the vane-type device 36 through the expansion chamber inlet56. In the vane-type device 36, the pressure and temperature of the airdecrease as the volume of the expansion chambers 50 increases. The airentering the vane-type device 36 then pushes the cooled anddepressurized air out of the vane-type device 36 through the expansionchamber outlet 58. The air then exits the flow path 24 through theoutlet 28 at a cooler temperature than it was when entering the flowpath 24, thereby cooling the target space 22.

FIG. 4 shows the vane-type device 36 in a heating open loop system.Similar to the embodiment of FIG. 3, the inlet 26 and the outlet 28 aredisposed in the target space 22 for using the air in the target space 22as the working fluid. In the embodiment of FIG. 4, the expansion chamberinlet 56 of the stator housing 38 is generally longitudinally alignedwith the compression chamber outlet 54 of the stator housing 38, and thecompression chamber inlet 52 of the stator housing 38 is generallylongitudinally aligned with the expansion chamber outlet 58 of thestator housing 38. A heat exchanger 32 disposed in the atmosphere 30 isfluidly connected to the expansion chamber outlet 58 and the compressionchamber inlet 52. In operation, the air of the target space 22 entersthe flow path 24 through the inlet 26, and the blower propels the airinto the vane-type device 36 through the expansion chamber inlet 56. Thepressure and temperature of the air decrease as the volume of theexpansion chambers 50 increases. The air leaves the vane-type device 36through the expansion chamber outlet 58 and flows to the heat exchanger32. In the heat exchanger 32, the cooled and depressurized air receivesheat from the atmosphere 30 before being propelled back into thevane-type device 36 through the compression chamber inlet 52 by anotherpump 60. The warmed and still depressurized air entering the vane-typedevice 36 through the compression chamber inlet 52 also pushes thecooled and depressurized air out of the vane-type device 36 through theexpansion chamber outlet 58. In the vane-type device 36, the pressureand temperature of the air increase as the volume of the compressionchambers 48 decreases. The air entering the vane-type device 36 throughthe expansion chamber inlet 56 then pushes the warmed and re-pressurizedair out of the vane-type device 36 through the compression chamberoutlet 54. The air then exits the flow path 24 through the outlet 28 ata warmer temperature than it was when entering the flow path 24, therebywarming the target space 22.

An open-loop air aspirated hybrid heat pump and heat engine system 20having a compressor 76 separated from the expander 78 is generally shownin FIG. 5. Similar to the embodiment of FIG. 1, atmospheric air is usedas the working fluid in the embodiment of FIG. 5. In the embodiment ofFIG. 5, the heat exchanger 32 is disposed in the target space 22 fortransferring heat between the air in the flow path 24 and the targetspace 22, and the inlet 26 and the outlet 28 are disposed outside of thetarget space 22 in the atmosphere 30. A compressor 76 is disposed in theflow path 24 between the inlet 26 and the heat exchanger 32 forcompressing and delivering the air from the inlet 26 to the heatexchanger 32. An expander 78 is disposed in the flow path 24 between theheat exchanger 32 and the outlet 28 for expanding (i.e. depressurizing)and delivering the air from the heat exchanger 32 to the outlet 28. Inthe exemplary embodiment, the compressor 76 and expander 78 are bothvane-type pumps having a cylindrically shaped stator 38 and a rotor 42rotatably disposed within the stator 38. A plurality of spring-loadedvanes 46 project outwardly from the rotor 42 to slidably engage theinner wall 44 of the stator 38. However, it should be appreciated thatthe compressor 76 and the expander 78 could be any type of pumps.

An energy receiving device is mechanically connected to the expander 78for harnessing potential energy from the air in the flow path 24 as willbe discussed in further detail below. In the exemplary embodiment, theenergy receiving device is a generator 68 for generating electricity.The electricity can then be used immediately, stored in batteries orinserted into the power grid. Alternatively or additionally, the energyreceiving device could be a mechanical connection between the expander78 and the compressor 76 for powering the compressor 76 with the energyreclaimed from the air in the flow path 24. The energy receiving devicecould also be any other device for harnessing the energy produced by theexpander 78.

A controller 82 is in communication with the compressor 76 and theexpander 78 for controlling the hybrid heat pump and heat engine system20. The controller 82 manipulates or switches the system 20 betweendifferent operating modes: a standard heating/cooling mode (in which thetarget space 22 can be either heated or cooled), and a high heating mode(in which the target space 22 is heated). The operating mode may beselected by a person, or the controller 82 can be coupled to athermostat for automatically keeping the target space 22 at a desiredtemperature.

In reference to FIG. 5, the working fluid (e.g., air) travels throughthe flow path 24 in a clockwise direction. In the standard coolingoperating mode, the controller 82 directs the compressor 76 to operateat a low speed and the expander 78 to operate at a higher speed. Whatfollows is that the compressor 76 functions similarly to a valveseparating the air downstream of the compressor 76 from the air at theinlet 26 of the flow path 24. The expander 78 then pulls the air alongthe flow path 24 by reducing the pressure of the air from the compressor76 to the expander 78. Persons skilled in the art will appreciate thatthe temperature of the air leaving the compressor 76 will decrease asthe pressure decreases. In other words, both the pressure andtemperature of the air on the downstream side of the compressor 76 arereduced when compared to the pressure and temperature of the air at theinlet. The depressurized and cooled air then flows through the heatexchanger 32, which transfers heat from the target space 22 to the airin the flow path 24 to cool the target space 22. After leaving the heatexchanger 32, the expander 78 propels the air out of the flow path 24through the outlet 28. Alternatively, the direction of the air may bereversed to flow in a counter-clockwise direction if this makes betteruse of the devices chosen with the final engineering targets in mind. Inthe cooling operating mode, the energy receiving device may bemechanically connected to the compressor 76 for harnessing the potentialpressure energy from the air flowing through the compressor 76.

In the standard heating mode, the controller 82 directs the compressor76 to compress the air from the inlet to increase the pressure and thetemperature of the air, as will be understood by those skilled in theart. The pressurized and warmed air then flows through the flow path 24to the heat exchanger 32. The heat exchanger 32 dispenses heat to thetarget space 22 to warm the target space 22. Although the air in theflow path 24 is cooled by the heat exchanger 32, the air remainspressurized when compared to the air entering the flow path 24. Thisdifference in pressure represents potential energy, which can beharnessed. The generator 68, which is coupled to the expander 78,harnesses this potential energy while the expander 78 expands thepressurized air to reduce the pressure of the air. Preferably, the airis expanded back to the same pressure at which it entered the flow path24. Following the expansion, the air is discharged from the flow path 24through the outlet 28.

In the high heating mode, the compressor 76 receives air aspirated fromthe inlet 26 and then compresses the air to increase its pressure andalso its temperature (in compliance with relevant thermodynamic gaslaws). The pressurized and high temperature air then flows through theflow path 24 to the combustion chamber 62, which mixes a suitable fuelwith the air and then combusts the mixture. The combustion of the fueland air mixture further increases both the pressure and the temperatureof the air in the flow path 24. The pressurized and heated air thenflows through the heat exchanger 32 and dispenses heat to the targetspace 22. Air leaving the heat exchanger 32 in the high heating moderemains substantially highly pressurized relative to the ambient airpressure, and therefore represents a valuable amount of potentialenergy. The generator 68 maybe of any suitable type that is effective toconvert this potential energy into another form, such as electricityand/or mechanical energy. This potential energy may be harnessed whilethe expander 78 expands the air to reduce the pressure of the air, oraccumulated for conversion at a later time. In other words, any residualpressure energy put into the air through the initial compression andcombustion processed is subsequently re-claimed by the generator 68.Once the potential energy has been reclaimed, the low pressure air isthen discharged from the flow path 24 through the outlet 28 back intothe environment 30.

Obviously, many modifications and variations of the present inventionare possible in light of the above teachings and may be practicedotherwise than as specifically described while within the scope of theappended claims. These antecedent recitations should be interpreted tocover any combination in which the inventive novelty exercises itsutility. The use of the word “said” in the apparatus claims refers to anantecedent that is a positive recitation meant to be included in thecoverage of the claims whereas the word “the” precedes a word not meantto be included in the coverage of the claims. In addition, the referencenumerals in the claims are merely for convenience and are not to be readin any way as limiting.

What is claimed is:
 1. A high-efficiency air moving system forcirculating ambient air in a target space across a heat exchanger, saidsystem comprising: a confined flow path for routing ambient air as aworking fluid from an inlet to an outlet, said inlet disposed to receiveambient air from the target space as the working fluid and said outletdisposed for expelling the air out of said flow path and back into theambient air in the target space, a first turbine disposed in said flowpath adjacent said inlet, said first turbine configured to controlsubstantially all of the movement of air entering said flow path throughsaid inlet, a second turbine disposed in said flow path adjacent saidoutlet, said second turbine configured to control substantially all ofthe movement of air exiting said flow path through said outlet, a heatexchanger disposed in said flow path between said first and secondturbine, said heat exchanger configured to move heat into or out of theair in said flow path and thereby heat or cool the air in the targetspace when the air is subsequently discharged from said outlet, andwherein movement of heat into or out of the air in said flow path causesa corresponding differentiated pressure of the air between said firstand second turbines relative to the ambient air, and at least one ofsaid first turbine and said second turbine being configured to harvestwork from the differentiated pressure of the air between said first andsecond turbines.
 2. The system as set forth in claim 1, furtherincluding an electric generator operatively coupled to one of said firstand second turbines for generating electricity from the harvested work.3. The system as set forth in claim 1, wherein at least one of saidfirst turbine and said second turbine comprises a positive displacementvane pump.
 4. The system as set forth in claim 1, further including atransmission in communication with said first turbine and said secondturbine, said transmission configured to transfer work harvested fromone of said first and second turbines directly to the other of saidfirst and second turbines.
 5. The system as set forth in claim 1,wherein said heat exchanger moves heat out of the air in said flow path,and said first turbine harvests work from the differentiated pressure ofthe air between said first and second turbines.
 6. The system as setforth in claim 1, wherein said heat exchanger moves heat into the air insaid flow path, and said second turbine harvests work from thedifferentiated pressure of the air between said first and secondturbines.
 7. The system as set forth in claim 1, further including acombustion chamber in said flow path between said first turbine and saidheat exchanger.
 8. A high-efficiency air moving system for circulatingambient air in a target space across a heat exchanger, said systemcomprising: a confined flow path for routing ambient air as a workingfluid from an inlet to an outlet, said inlet disposed to receive ambientair from the target space as the working fluid and said outlet disposedfor expelling the air out of said flow path and back into the ambientair in the target space, a first pump disposed in said flow pathadjacent said inlet, said first pump configured to control substantiallyall of the movement of air entering said flow path through said inlet, asecond pump disposed in said flow path adjacent said outlet, said secondpump configured to control substantially all of the movement of airexiting said flow path through said outlet, a heat exchanger disposed insaid flow path between said first and second pump, said heat exchangerconfigured to move heat into or out of the air in said flow path andthereby heat or cool the air in the target space when the air issubsequently discharged from said outlet, and wherein movement of heatinto or out of the air in said flow path causes a correspondingdifferentiated pressure of the air between said first and second pumpsrelative to the ambient air, and at least one of said first pump andsaid second pump being configured to harvest work from thedifferentiated pressure of the air between said first and second pumps.9. The system as set forth in claim 8, further including an electricgenerator operatively coupled to one of said first and second pumps forgenerating electricity from the harvested work.
 10. The system as setforth in claim 8, wherein at least one of said first pump and saidsecond pump comprises a positive displacement vane pump.
 11. The systemas set forth in claim 8, further including a transmission incommunication with said first pump and said second pump, saidtransmission configured to transfer work harvested from one of saidfirst and second pumps directly to the other of said first and secondpumps.
 12. The system as set forth in claim 8, wherein said heatexchanger moves heat out of the air in said flow path, and said firstpump harvests work from the differentiated pressure of the air betweensaid first and second pumps.
 13. The system as set forth in claim 8,wherein said heat exchanger moves heat into the air in said flow path,and said second pump harvests work from the differentiated pressure ofthe air between said first and second pumps.
 14. The system as set forthin claim 8, further including a combustion chamber in said flow pathbetween said first pump and said heat exchanger.
 15. A high-efficiencyair moving system for circulating ambient air in a target space across aheat exchanger, said system comprising: a confined flow path for routingambient air as a working fluid from an inlet to an outlet, said inletdisposed to receive ambient air from the target space as the workingfluid and said outlet disposed for expelling the air out of said flowpath and back into the ambient air in the target space, a first positivedisplacement vane pump disposed in said flow path adjacent said inlet,said first positive displacement vane pump configured to controlsubstantially all of the movement of air entering said flow path throughsaid inlet, a second positive displacement vane pump disposed in saidflow path adjacent said outlet, said second positive displacement vanepump configured to control substantially all of the movement of airexiting said flow path through said outlet, a heat exchanger disposed insaid flow path between said first and second positive displacement vanepumps, said heat exchanger configured to move heat into or out of theair in said flow path and thereby heat or cool the air in the targetspace when the air is subsequently discharged from said outlet, andwherein movement of heat into or out of the air in said flow path causesa corresponding differentiated pressure of the air between said firstand second positive displacement vane pumps relative to the ambient air,and at least one of said first positive displacement vane pump and saidsecond positive displacement vane pump being configured to harvest workfrom the differentiated pressure of the air between said first andsecond positive displacement vane pumps.
 16. The system as set forth inclaim 15, further including an electric generator operatively coupled toone of said first and second positive displacement vane pumps forgenerating electricity from the harvested work.
 17. The system as setforth in claim 15, further including a transmission in communicationwith said first positive displacement vane pump and said second positivedisplacement vane pump, said transmission configured to transfer workharvested from one of said first and second positive displacement vanepumps directly to the other of said first and second positivedisplacement vane pumps.
 18. The system as set forth in claim 15,wherein said heat exchanger moves heat out of the air in said flow path,and said first positive displacement vane pump harvests work from thedifferentiated pressure of the air between said first and secondpositive displacement vane pumps.
 19. The system as set forth in claim15, wherein said heat exchanger moves heat into the air in said flowpath, and said second positive displacement vane pump harvests work fromthe differentiated pressure of the air between said first and secondpositive displacement vane pumps.
 20. The system as set forth in claim15, further including a combustion chamber in said flow path betweensaid first positive displacement vane pump and said heat exchanger.